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We consider a single server phase type queueing model with server vacation, repair, breakdown, degrading service, starting failure and closedown. When the arrival rate of the customer follows the Markovian Arrival Process (MAP) and the service rate of the server follows the phase-type distribution. If no one is in the system when the server is back from the vacation, then the server will wait until the customer arrives. If the customer arrives at the moment with no starting failure, then he provides service, otherwise the server immediately goes to the repair process. Here, the service rate declining until degradation fixed. After completion of K services the degradation is addressed. During the period of service, the server may get a breakdown at any moment, and then the server immediately goes for a repair process. After completing the service, he switches to the close-down process, and then he goes on vacation. Using the Matrix-Analytic method, The stationary probability vector representing the total number of customers in the system is examined. The analysis of the busy period, the mean waiting time, and cost analysis are discussed. A few significant performance measures are attained. Finally, some numerical examples are given.

In this work, the influence of varying mixing ratios of O-2 on positive streamer initiation in supercritical (SC) CO2 at different applied voltages was investigated using a 3-D particle model. Zener's model was included in the 3-D particle model to calculate the field ionization rate during streamer formation and propagation. The evolution of positive streamer was classified into three main stages namely inception cloud, primary streamer channels, and successive streamer branching. The effect of O-2 with different mixing ratios (2%, 10%, and 20%) on the morphology, average electron density, electric field distribution, streamer length, and electron energy distribution function (EEDF) for positive streamer in SC-CO2 at four different voltages (12, 12.5, 13, and 13.5 kV) is then investigated. The 2-D cross sections of the initial stage of the streamer and the electric field distribution are presented in detail. At the same applied voltage, the size of inception cloud, average electron density, electric field, and streamer length with the maximum electric field decreased with increasing oxygen concentration in SC-CO2. With increasing applied voltage, the apparent size of inception cloud, primary streamer channels, successive streamer branching, average electron density, electric field, and streamer length increased. The simulation results showed that adding O-2 to SC-CO2 can significantly affect the streamer initiation and propagation.

THE PURPOSE. Comprehensive study of the effect of direct current electric discharge plasma in a gas-liquid medium of inorganic mixtures in order to obtain gaseous hydrogen. Obtain volt-ampere, volt-second and ampere-second characteristics of the discharge at various concentrations of electrolyte. Study the process of electrolysis, breakdown, discharge ignition and discharge flow in a dielectric tube at a constant current. METHODS. To solve this problem, experimental studies were carried out on a model installation, which consists of a power supply system, a discharge chamber, equipment for monitoring and controlling the operation of the installation and measuring the characteristics of an electric discharge. To analyze the stability of the discharge, the time dependences of the voltage ripple and the discharge current were obtained. RESULTS. Experimental studies were carried out between the electrolytic cathode and the electrolytic anode at constant current and at atmospheric pressure with the following parameters: discharge voltage U = 0.1-1.5 kV, discharge current I = 0.02-2.3 A, interelectrode distance l = 100 mm , 1%, 3% and 5% solutions of sodium chloride in tap water were used as electrolytes. CONCLUSION. It is shown that electrical breakdown and ignition of a discharge that is stable in time depends on the conductivity of the gas-liquid medium of the electrolyte. The nature of the current-voltage characteristics depends on the random processes occurring in the gas-liquid medium, which is associated with numerous breakdowns occurring in the gas-liquid medium of the electrolyte, combustion and attenuation of microdischarges, the appearance of bubbles, and the movement of the electrolyte inside the dielectric tube. It is shown that the generation of hydrogen and hydrogen-containing components can occur both at the stage of electrolysis and during discharge combustion. A feature of this method is that electrical discharges in the tube increase the release of hydrogen. In this installation, inorganic and organic liquids of a certain composition and concentration can be used. The results of experimental studies made it possible to develop and create a small-sized installation for producing gaseous hydrogen. Tests have shown that a small-sized plant can be taken as the basis for a industrial plant for the production of hydrogen gas.

Surface roughness represents the measure of the irregularities on the surface contributing to the local field enhancement. The traditional Fowler-Nordheim equation established for perfectly planar surfaces is not suitable for describing emission from rough surfaces. Instead, it is more appropriate to use the equation that accounts for the field enhancement factor describing the effect of the surface morphology. In superconducting radio frequency cavities, field emission may occur in the irises while the tips on the cavity surface may act as an emitter leading to the high electric field. For this study, calculations for hemispherical, cylindrical, and conical tips have been performed using a Multiphysics software package COMSOL. The focus was put on the dependence of the field enhancement factor on the shape and the radius of the protrusions. The electric field strength and the current density increase with increasing the root mean square average of the profile heights due to field enhancement at the cavity irises. The lowest value of the electric field has been achieved for the hemisphere. The calculated values for the field enhancement factors are consistent with the data from the literature, in which case the protrusion may represent a small local bump on the surface of a superconducting cavity. Based on the fit of the results, presented here, the relation between the enhancement factor and the radius has been suggested. The accurate estimation of the field emission may play a crucial role in the design of accelerators and other technological applications with requirements of extremely high precision.

Over the last half century, the existence of an additional thermal transition in between the glass transition and the Curie/melting transition has been frequently observed on vinylidenefluoride-based ferro-, pyro- and piezoelectric homo- and co-polymers. The transition has also been observed recently in some of the related relaxor-ferroelectric terpolymers. Despite its well-known existence and the rich history of its treatment in the literature, the origin(s) and a more or less complete picture of the mid-temperature transition have remained elusive until now. Over the years, several authors have put forth various explanations for the so-called mid-temperature transition — some complementary and some contradictory to each other. At the 17th IEEE International Symposium on Electrets (ISE-17) in Limerick, Ireland, in September 2019, the mysterious mid-temperature transition and its possible mechanism(s) became the subject of a panel discussion a) to mark the Golden Jubilee of the discovery of piezoelectricity in polyvinylidenefluoride (PVDF) by Heiji Kawai of Kobayashi Institute of Physical Research, Japan, as well as the Centennial of the first recognition of ferroelectricity in piezoelectric Seignette's or Rochelle salt. The panel put forward a new hypothesis that the mid-temperature transition is most likely a result of several interrelated processes that take place within the respective temperature range. The relevant processes include an upper glass transition or relaxation, a relaxation related to conformational disorder, possible imperfect/time-dependent structures formed as a result of thermal processing and secondary crystallization, as well as interface polarization effects at crystalline-amorphous boundaries. The article captures the essence of the panel discussion and the perspectives obtained therefrom to elucidate the complex mid-temperature transition in vinylidenefluoride-based ferro-, pyro- and piezoelectric homo-, co- and ter-polymers.

Purpose Life cycle assessment (LCA) is an internationally accepted method to assess the environmental impacts of buildings. A major methodological challenge remains the modelling of the end-of-life stage of buildings and allocation of benefits and burdens between systems. Various approaches are hence applied in practice to date. This paper compares the two methods widely renowned in Europe—the EC product environmental footprint (PEF) method and the CEN standards: EN 15804+A1 and EN15978—and offers insights about their fitness for achieving circularity goals. Methods The EC PEF method and the CEN EN 15804/EN 15978 standards were methodologically analysed with a focus on the end-of-life modelling and allocation approach and were applied to a building case study. The EN 15804+A1 standard explains the guidelines but does not offer a modelling formula. Accordingly, this paper proposes a formula for the CEN standards using identical parameters as in the end-of-life circular footprint formula (CFF) of the EC PEF Guidance v6.3 to increase consistency among LCA studies. The calculation formulas were then applied to a newly constructed office building. A comparative analysis of both the implementation and results are described, and recommendations are formulated. Results In the absence of databases compatible with the two LCA methods and comprising all building products, the Ecoinvent datasets had to be remodelled to enable a comparative modular assessment. This proved to be a laborious process. The EC PEF method and CEN standards showed similar impacts and hotspots for the case study building. The module D in the CEN standards includes a significant share of positive impacts, but due to collective accounting, it does not clearly communicate these benefits. The summation of burdens and benefits in the EC PEF method reduces its transparency, while the allocation and quality factors enable this method to better capture the market realities and drive circular economy goals. Conclusions The construction sector and the LCI database developers are encouraged to create the missing LCA databases compatible with the modular and end-of-life allocation modelling requirements of both methods. More prescriptive and meticulous guidelines, with further harmonization between the EC PEF method and the CEN standards and their end-of-life allocation formula, would largely increase comparability and reliability of LCA studies and communications. To improve transparency, it is recommended to report the module D impacts per life cycle stage as per the CEN standards and the burdens and benefits separately for each life cycle stage as per the EC PEF method.

Electrical energy affect to economic, electrical energyconsumption will increase and decrease likely economics. In this globalization era, electricity consumption was increased trendyearly since industrialization era. The reliability Electrical energy is very importantfor economic growth. The lower SAIDI and SAIFI is the bench mark for reliability of electrical energy supply. The reliable of insulator cover type: YSL-70-AP affect to the reliability electrical distribution energy on over head distribution circuit. Insulator cover protected to over head distribution circuit againt animal, bird, tree ang other temporarydisturbance. Insulator cover also to protect half insulated medium voltage cable againtpartial discharge and flashover. Over voltage stress more often during operation, to impact to the material insulationperformance.This quantitative research founding: insulator cover type: YSL-70-AP still feasible to use after voltage breakdown stress. The fault current is still under the maximum allowable leakage current (11,600 micro ampere) which is 41.61 micro ampere, and breakdown voltage is still higher than minimum that specified (24 kilo volt), which is 49.63 kilo volt.Post breakdown voltage the material insulation performance of insulator cover type: YSL-70-APis good, and reliable to continuous operation over head distribution circuit.

This paper provides a comparative study on the impulse breakdown performance of SF 6 and 20% C 3 F 7 CN / 80% CO 2 gas mixture under weak non-uniform electric fields. Two geometrically distinct electrode configurations, with similar field utilization factor, were subjected to standard lightning impulse waveform (1.2/50 μs) and the effects of pressure, gap distance and impulse polarity on breakdown characteristics were studied. The results show that SF 6 has a higher breakdown voltage than the C 3 F 7 CN/CO 2 mixture and the positive 1.2/50 μs breakdown voltages were found to be higher than the negative counterparts. These results show that the effect of polarity on breakdown voltage does not exclusively depend on electrode geometry but also on pressure and gas type. The results of this paper identify the weaker polarity for 20% C3F7CN / 80% CO2 tested with hemispherical rod-plane and coaxial electrode configurations and the results contribute to the design of SF 6 -free gas insulated equipment.

Personalist autocracy is on the rise globally. Dictators’ increasing tendency to concentrate power in their own hands has major implications for the political stability of autocracies. However, the exact nature of this impact is unclear. On the one hand, regime personalization has been linked to a reduction in the likelihood of coups. On the other hand, personalization has also been linked to an increase in the likelihood of civil war. This article reconciles these findings and argues that personalization involves a trade-off between different kinds of threats against a dictator. By increasing the degree of personalization, dictators reduce their vulnerability to insider challenges while at the same time increasing their vulnerability to outsider challenges. These expectations are corroborated by a time-series cross-sectional analysis of a global sample of autocratic regimes. The findings help shed light on recent instances of longstanding autocrats being overthrown during episodes of mass mobilization.

In this paper, results of investigation on the impact of firing temperature on insulating properties of Low Temperature Cofired Ceramics are presented. Dissipation factor, volume resistivity and breakdown electric field intensity were determined for firing peak temperature in the range from 800 °C to 900 °C. The tests were performed for two commercial LTCC materials: 951 Green Tape (DuPont, USA) and SK47 (Keko, Slovenia). The results showed that the firing temperature had a significant effect on the dielectric loss factor, volume resistivity and lifetime at applied high voltage. No clear tendency was observed for dielectric strength in the analyzed firing temperature range.

ispartof: 2022 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM (IRPS) ispartof: IEEE International Reliability Physics Symposium (IRPS) location:TX, Dallas date:27 Mar - 31 Mar 2022 status: published

In this work, a vertical gallium nitride (GaN)-based trench MOSFET on 4-inch free-standing GaN substrate is presented with threshold voltage of 3.15 V, specific on-resistance of 1.93 mΩ·cm2, breakdown voltage of 1306 V, and figure of merit of 0.88 GW/cm2. High-quality and stable MOS interface is obtained through two-step process, including simple acid cleaning and a following (NH4)2S passivation. Based on the calibration with experiment, the simulation results of physical model are consistent well with the experiment data in transfer, output, and breakdown characteristic curves, which demonstrate the validity of the simulation data obtained by Silvaco technology computer aided design (Silvaco TCAD). The mechanisms of on-state and breakdown are thoroughly studied using Silvaco TCAD physical model. The device parameters, including n−-GaN drift layer, p-GaN channel layer and gate dielectric layer, are systematically designed for optimization. This comprehensive analysis and optimization on the vertical GaN-based trench MOSFETs provide significant guide for vertical GaN-based high power applications.

The purpose of this paper is to analyse a single server queueing model with multiple vacations, optional service, close-down, setup, balking, breakdown and repair under the assumption that the customers arrive according to a Markovian Arrival Process (MAP). The service and repair times follow the phase-type distributions. At the completion of service, in case there are no customers in the system, the server closes down the system and goes for vacation. After completion of the vacation, the server has to start the setup process if a minimum of one customer is present in the system or else the server goes for another vacation. The server provides optional service to the customers those who are in need of additional services. By employing the matrix analytic method, the stationary probability vector has been evaluated. The stability condition, busy period analysis, distribution function for waiting time and some of the system performance measures concerning this model are derived. The outcome arising out of numerical values and graphical representations are also presented for this model.

Self-assembled monolayers (SAMs) are the emerging materials to act as barriers in the back-end-of-line interconnects for advanced technological nodes. In this study, SAMs were formed on the porous SiOCH (p-SiOCH) films by using different precursors: 3-Aminopropyltrimethoxysilane (APTMS) or decyltrimethoxysilane (DTMOS), in the vapor phase. Effects of SAMs precursors on the electrical characteristics and reliability of p-SiOCH films were characterized and compared. Experimental results indicated that both SAMs derived from APTMS and DTMOS enhanced the breakdown field and time-dependent dielectric breakdown, provided Cu barrier capacity, and promoted adhesion with Cu. In particular, APTMS-SAMs had a larger improvement, but a larger increase in the dielectric constant was observed as compared to DTMOS-SAMs. Therefore, SAMs derived from APTMS are a promising candidate for sub-nanometer barrier application for advanced interconnects.

The paper presents the results of a study of the electric strength of a polypropylene film with a thickness of 2 μm. The breakdown voltage of the film was determined under the influence of electric pulses and with a slowly increasing voltage. The rate of increase in voltage at the pulse front varied from 1.8 to 78 GV/s, and with a slowly increasing voltage it varied from 28 to 1100 V/s. A statistical analysis of the breakdown voltage data was performed. For both modes of electrical testing and at all rates of voltage increase, the most probable breakdown voltages Fbr.exp were calculated. The effect of the voltage rise rate on the value of Fbr.exp was not detected. The obtained values Fbr.exp were approximately the same for both test modes and amounted to 550 MV/m for DC and 570 MV/m for pulses.

It is well known that radio frequency breakdown is one of the main limitations in high frequency accelerators. Similarities have been detected between breakdowns in direct current vacuum gaps and those in superconducting radio frequency cavities. Therefore, cavity break- downs due to electric field phenomena can be understood by studying direct current vacuum breakdowns. Significant irregularity of a surface and a variety of involved processes objectively stipulate a number of factors which may lead to a breakdown. In this paper, the effects of surface conditions, accelerator gradient, pulse length, and operating frequency on the breakdown have been studied by using COMSOL simulation package. It was found that the dependence of breakdown rate on accelerating gradient and pulse length follows scaling laws. Based on the time evolutions of electron density and the potential in cone-cylinder electrode configuration at the pressure of 0.1 Pa, the time scale of a vacuum breakdown has been established. It was also confirmed that the emission from an electrode surface can be regarded as a major factor leading to electrical breakdown in vacuum. The obtained results could be very useful in high-gradient accelerating structures.

The electrical tree initiation and propagation behaviors are a key issue for the polyethylene-based cable insulation. This paper focuses on the effect of crystalline morphology on electrical tree growth characteristics of high-density and low-density polyethylene (HDPE/LDPE) blend insulation. In this paper, the electrical tree growth characteristics of HDPE/LDPE blends with HDPE mass fractions of 0, 10, 15, 20 wt% are investigated under repetitive impulse voltage at 40, 60, 80 °C. It is found that with the rise of HDPE content from 0 to 15 wt%, the growth rate and accumulated damage of electrical tree decreases, with the morphology of electrical tree tending to bush tree. The increasing of voltage amplitude improves the energy of injected charge while the temperature rise leads to the relaxation of molecular chain, which both result in the promotion of collision ionization, thus increasing the density of electrical tree. Compared with branch tree, bush tree illustrates better inhibition of discharge tracks due to uniform electric field at the end of branches. The crystalline characteristics of HDPE/LDPE blends indicate that the crystallinity increases with the addition of HDPE, and the blend comprising 15 wt% HDPE in an LDPE matrix apparently reduces the average size of spherulites and improves the distribution of spherulites evenly. The upsurge of crystal-amorphous interface leads to the increase of deep trap energy level density and the decrease of carrier mobility. Carrier injection and migration at the interface between crystalline and amorphous regions are restrained, thus inhibiting the growth of electrical tree. It is concluded that the crystalline morphology modified by polymer blending has a significant effect on the electrical tree growth characteristics.

Understanding the DC breakdown characteristics of polymeric insulators is essential for stable operation of high-capacity DC electrical equipment. To predict the breakdown characteristics of low-density polyethylene (LDPE), we propose a numerical methodology with a new critical index in which the internal current varying with temperature, thickness, and injection barrier height. To evaluate this current-based index, we applied the fully coupled bipolar charge transport (BCT) and molecular chain displacement (MCD) models to analyze the influence of each variable on breakdown phenomena. The results of this analysis revealed that the amount of space charge accumulation within the insulator has a maximum value at approximately 50 °C, which corresponds to the known morphological transition temperature of LDPE. The breakdown strength calculated using this numerical model was found to decrease with increasing temperature and thickness. Although injection barrier height at the electrode was found to be negatively correlated with breakdown strength, its effect was not as significant as that of the other variables. The breakdown strength values obtained using this numerical method were found to be in close agreement with values reported in the literature. Based on these results, we newly suggest the physical quantity to predict the breakdown strength, the current relaxation speed, which is the slope of the Boltzmann sigmoid function, as a positively correlated index. Finally, we determined that the breakdown phenomena are initiated when the amount of impact accumulated in the insulator changes discontinuously and analyzed the contribution of factors affecting the breakdown using the Pearson correlation coefficient and the Sobol sensitivity index.

Percutaneous transluminal angioplasty is a well-known treatment for arteriovenous fistula stenosis. Balloon rupture during endovascular procedures is a rare but possible complication. The bursting balloon itself does not cause a serious problem, but it can occasionally cause entrapment, especially in case of breakdown of the balloon catheter tip. Here, we present four cases of balloon rupture during angioplasty in the hemodialysis circuit. In three cases, the ruptured balloon catheter was removed by cutdown of access conduit, while in one case, tip of ruptured balloon catheter was migrated into the pulmonary artery and was removed surgically. The operator must attempt to reduce the risk of balloon rupture by gradually expanding the balloons under bursting pressure. If the balloon bursts, it should not be removed excessively and attempt should be made to remove it using endovascular techniques. Surgical removal is considered after careful evaluation of the condition of the balloon and vessel.

International audience; This text proposes to describe and analyze artistic practices that bring out a subversive approach to technologies. It is a matter of reporting on gestures that are doubly inscribed in the history of art (counter-cultures) and “technocritics”, at the heart of which the digital machine becomes a material to be altered and diverted in order to better understand them (dys)functions. It is therefore on the side of their inefficiency, their failure, their overflow that we question the machines in order to identify the forms of a possible aesthetic of breakdown: which means being attentive to their imbalances, machinations, paranoid states.The examination of these contemporary artistic practices can revive various tactics or or well-known tricks of anthropology: DIY (low tech, bug, glitch, datamosh), poaching (intrusion, looting, re-use, diversion), sabotage (desecration, counter-employment, virus, breakage). We show how (dis)playing the breakdown and “doing artwork” covers here social and political as well as aesthetic issues: autonomy, independence, critical reflexivity, reappropriation of material cultures, against obsolescence and against the opacity of systems.‪; Ce texte propose de décrire et d’analyser des pratiques artistiques qui font émerger une approche subversive des technologies. Il s’agit de rendre compte de gestes doublement inscrits dans l’histoire de l’art (contre-cultures) et des « technocritiques », au cœur desquels la machine numérique devient une matière à altérer et à détourner afin de mieux en saisir les (dys)fonctionnements. C’est par conséquent du côté de leur inefficacité, de leur défaillance, de leur débordement que nous interrogeons ici les machines afin d’identifier les formes d’une possible esthétique de la panne : ce qui implique d’être attentif à leurs déséquilibres, machinations, états paranoïaques.L’examen de ces pratiques artistiques contemporaines permet de raviver différentes tactiques ou ruses bien connues de l’anthropologie : le bricolage (basse définition, bug, glitch, datamosh), le braconnage (intrusion, pillage, réemploi, détournement), le sabotage (profanation, contre emploi, virus, casse). Nous montrons comment (dé)jouer la panne et « faire œuvre » recouvrent ici des enjeux sociaux et politiques autant qu’esthétiques : autonomie, indépendance, réflexivité critique, réappropriation des cultures matérielles, contre l’obsolescence et contre l’opacité des systèmes.

Future shifts of the austral midlatitude jet are subject to large uncertainties in climate model projections. Here we show that, in addition to other previously identified sources of inter-model uncertainty, changes in the timing of the stratospheric polar vortex breakdown modulate the austral jet response to greenhouse gas forcing during summertime (December-February). The relationship is such that a larger delay in vortex breakdown favors a more poleward jet shift, with an estimated 0.7-0.8-degree increase in jet shift per 10 days delay in vortex breakdown. The causality of the link between the timing of the vortex breakdown and the tropospheric jet response is demonstrated through climate modeling experiments with imposed changes in the seasonality of the stratospheric polar vortex. The vortex response is estimated to account for about 30% of the inter-model variance in the shift of the summertime austral jet, and about 45% of the mean jet shift.

Simple Summary Major angiogenic growth factors activate downstream signaling cascades by interacting with both receptor tyrosine kinases (RTKs) and cell surface proteoglycans, such as heparan sulfate proteoglycans (HSPGs). As current anti-angiogenesis regimens in cancer are often faced with resistance, alternative therapeutic strategies are highly needed. The aim of our study was to investigate the impact on angiogenic signaling when we interfered with growth factor-HSPG interactions using a CXCL9 chemokine-derived peptide with high affinity for HS. Growth factors such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) and epidermal growth factor (EGF) are important angiogenesis-mediating factors. They exert their effects not only through their respective receptor tyrosine kinases (RTKs), but they also require molecular pairing with heparan sulfate proteoglycans (HSPGs). Angiogenic growth factors and their signaling pathways are commonly targeted in current anti-angiogenic cancer therapies but have unfortunately insufficient impact on patient survival. Considering their obvious role in pathological angiogenesis, HS-targeting drugs have become an appealing new strategy. Therefore, we aimed to reduce angiogenesis through interference with growth factor-HS binding and downstream signaling using a CXCL9-derived peptide with a high affinity for glycosaminoglycans (GAGs), CXCL9(74-103). We showed that CXCL9(74-103) reduced EGF-, VEGF165- and FGF-2-mediated angiogenic processes in vitro, such as endothelial cell proliferation, chemotaxis, adhesion and sprouting, without exerting cell toxicity. CXCL9(74-103) interfered with growth factor signaling in diverse ways, e.g., by diminishing VEGF165 binding to HS and by direct association with FGF-2. The dependency of CXCL9(74-103) on HS for binding to HMVECs and for exerting its anti-angiogenic activity was also demonstrated. In vivo, CXCL9(74-103) attenuated neovascularization in the Matrigel plug assay, the corneal cauterization assay and in MDA-MB-231 breast cancer xenografts. Additionally, CXCL9(74-103) reduced vascular leakage in the retina of diabetic rats. In contrast, CXCL9(86-103), a peptide with low GAG affinity, showed no overall anti-angiogenic activity. Altogether, our results indicate that CXCL9(74-103) reduces angiogenesis by interfering with multiple HS-dependent growth factor signaling pathways.

Self-assembled monolayers (SAMs) are emerging as materials that are candidates of barriers used in back-end-of–line interconnects of integrated circuits for future generations. In this study, SAMs were formed on the SiO2 and porous SiOCH (p-SiOCH) films by using decyltrimethoxysilane (DTMOS) precursor in vapor phase at a temperature of 100 °C. The effects of the formation of SAMs at the surfaces of SiO2 and p-SiOCH films on the electrical characteristics were characterized and compared. With O2 plasma irradiation, SAMs could successfully form on both SiO2 and p-SiOCH films, thereby enhancing the adhesion and dielectric breakdown field. In the p-SiOCH films, SAMs sealed the surface pores and had higher coverage, promoting the effectiveness of the Cu barrier. In the Cu/porous low-k integrated interconnects for advanced technological nodes, therefore, SAMs are promising emerging materials acting as a barrier and adhesive. On the other hand, for SiO2 films, SAMs weakened the barrier; however, they can act as an interfacial adhesion enhancer.

В статье рассматриваются вопросы строительства подстанции 500/220/10 кВ «Алма». Целью работы является оценка точности методов разбивочных работ и усовершенствовании методики разбивочных работ путем рационального сочетания традиционного метода и метода GPS – измерений. Усовершенствование методики разбивочных работ при строительстве подстанции с использованием GPS технологий позволяет увеличить точность разбивочных работ и производительность труда., The article discusses the construction of a substation 500/220/10 kV "Alma". The aim of the work is to assess the accuracy of the methods of center work and to improve the methods of center work by a rational combination of the traditional method and the method of GPS measurements. The improvement of the methods of center work during the construction of a substation using GPS technologies allows to increase the accuracy of center work and labor productivity.

Electro-absorption (EA) waveguide-coupled modulators are essential building blocks for on-chip optical communications. Compared to state-of-the-art silicon (Si) devices, graphene-based EA modulators promise smaller footprints, larger temperature stability, cost-effective integration and high speeds. However, combining high speed and large modulation efficiencies in a single graphene-based device has remained elusive so far. In this work, we overcome this fundamental trade-off by demonstrating the 2D-3D dielectric integration in a high-quality encapsulated graphene device. We integrated hafnium oxide (HfO2) and two-dimensional hexagonal boron nitride (hBN) within the insulating section of a double-layer (DL) graphene EA modulator. This combination of materials allows for a high-quality modulator device with high performances: a ~39 GHz bandwidth (BW) with a three-fold increase in modulation efficiency compared to previously reported high-speed modulators. This 2D-3D dielectric integration paves the way to a plethora of electronic and opto-electronic devices with enhanced performance and stability, while expanding the freedom for new device designs., Here, three-dimensional hafnium oxide and two-dimensional hexagonal boron nitride are integrated in the insulating section of double-layer graphene optical modulators, leading to a maximum bandwidth of 39 GHz and enhanced modulation efficiency.

Article number 112706 The SMall Aspect Ratio Tokamak (SMART) device is a new compact (plasma major radius Rgeo≥0.40 m, minor radius a≥0.20 m, aspect ratio A≥1.7) spherical tokamak, currently in development at the University of Seville. The SMART device has been designed to achieve a magnetic field at the plasma center of up to Bϕ=1.0 T with plasma currents up to Ip=500 kA and a pulse length up to τft=500 ms. A wide range of plasma shaping configurations are envisaged, including triangularities between −0.50≤δ≤0.50 and elongations of κ≤2.25. Control of plasma shaping is achieved through four axially variable poloidal field coils (PF), and four fixed divertor (Div) coils, nominally allowing operation in lower-single null, upper-single null and double-null configurations. This work examines phase 2 of the SMART device, presenting a baseline reference equilibrium and two highly-shaped triangular equilibria. The relevant PF and Div coil current waveforms are also presented. Equilibria are obtained via an axisymmetric Grad-Shafranov force balance solver (Fiesta), in combination with a circuit equation rigid current displacement model (RZIp) to obtain time-resolved vessel and plasma currents. Feder (UE) US-15570 Feder (UE) IE17-5670 Horizonte 2020 (Unión Europea) 805162

[EN]Leaf litter decomposition is a key process in stream ecosystems, the rates of which can vary with changes in litter quality or its colonization by microorganisms. Decomposition in streams is increasingly used to compare ecosystem functioning globally, often requiring the distribution of litter across countries. It is important to understand whether litter sterilization, which is required by some countries, can alter the rates of decomposition and associated processes. We examined whether litter sterilization with gamma irradiation (25 kGy) influenced decomposition rates, litter stoichiometry, and colonization by invertebrates after weeks of instream incubation within coarse-mesh and fine-mesh litterbags. We used nine plant species from three families that varied widely in litter chemistry but found mostly consistent responses, with no differences in decomposition rates or numbers of invertebrates found at the end of the incubation period. However, litter stoichiometry differed between irradiated and control litter, with greater nutrient losses (mostly phosphorus) in the former. Therefore, the effects of irradiation on litter chemistry should be taken into account in studies focused on stoichiometry but not necessarily in those focused on decomposition rates, at least within the experimental timescale considered here. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The study was funded by Basque Government funds (IT951-16) to the UPV/EHU Stream Ecology Group.

Calcium carbonate (CaCO3) is an inorganic material which has been introduced in polymeric insulation to improve the thermal and electrical properties of insulation. In this research, a comparative study was performed between unfilled polypropylene (PP) and PP nanocomposites containing 5 wt% of CaCO3 nanofiller. The electrical breakdown performances of unfilled PP and nanocomposites were investigated. The chemical content of the material was carried out using Fourier transform infrared (FTIR) spectroscopy. The findings showed that the introduction of CaCO3 to the PP altered the chemical bonding of the material, where two additional characteristic absorption bands appeared in the FTIR spectra of PP/CaCO3 nanocomposites. In addition, PP/CaCO3 nanocomposites had slight changes on the AC breakdown strength compared to unfilled PP. Meanwhile, the DC breakdown performance of the nanocomposites was apparently lower than that of unfilled PP. These were attributed to the agglomeration of CaCO3.

Pulsed electro-acoustic (PEA) is well known as a non-destructive technique for testing and describing space charge profiles in the insulation. Degradation due to moisture, ageing, external flashover, partial discharge and space charge are considered as insulation defects that is an issue in high voltage insulator. Space charge may distort the internal electric field that may lead to an electrical breakdown. For instance, a method based on an acoustic phenomenon can be used to describe the space charge profiles. This paper compares several earlier researches on different specimen of PEA method and reviews their results to find the space charge distribution profiles. The scope of the review includes types of methods used. The acoustic technique is considered for this study. It has been observed that the PEA technique successfully gives the same result as theoretical that is based on the obtained profile. Linear low-density polyethylene (LLDPE) composite demonstrates about 89 % lower charge density value compared to cross-linked polyethylene (XLPE) and polypropylene (PP) composite. While the electric field value of ethylene-vinyl acetate (EVA) sample is 75 % lower than low-density polyethylene (LDPE) sample. This study found that the time interval, specimen thickness and the electric field sway the space charge profiles.

Concentrations of several toxic disinfection by-products (DBP), notably haloacetonitriles (e.g., trichloroacetonitrile, TCAN) and haloketones (e.g., di- and trichloropropanone, DCPN and TCPN, respectively) are affected by chlorination conditions and the inherent instability of these DBPs. In this study, effects of temperature, chlorine dose and reaction time on the formation of TCAN, DCPN and TCPN were interpreted using the approach of differential absorbance spectroscopy. Experimental data obtained for a wide range of water quality conditions demonstrate that in some cases the concentrations of some of the unstable DBPs increased rather than decreased at low temperatures and realistically long contact times. Despite the presence of pronounced changes of the kinetics of generation and degradation of these DBPs at varying temperatures and chlorine doses, their concentrations were strongly correlated with the concurrent changes of spectroscopic properties of DOM quantified via differential absorbance measurements at 272 nm (ΔA272). The maximum values of TCAN, DCPN and TCPN concentrations observed for the chlorination of eight different surface waters occur at the relative decreases of absorbance at 272 nm (defined as RΔA272) values of ca. 0.32 (±0.03), 0.24 (±0.05), and 0.42 (±0.03), respectively. The activation energies of degradation reactions of unstable DBPs were examined and the results indicate that TCAN and TCPN are caused by their hydrolysis with OH− while the degradation of DCPN is mainly caused by halogenation reaction with HOCl. These results in this study may be important for controlling the formation of unstable DBPs and further optimization of drinking water treatment.

Transformer is considered as one of the most important equipment in electrical power system networks. However, most problems occurred in transformer were related to the defects and weakness of the insulation systems. The oils used in transformer act as coolant and insulation purposes hence maintaining the dielectric strength of the transformer. In this work, electric field bridging pattern is observed from pre-breakdown and breakdown condition. The electric field bridging formation was recorded in the experimental setup and images were captured per frame. 193 images were randomly chosen from the whole video frames where 102 images were the pre-breakdown images and 91 images were the breakdown images. This system comprises of four stages: (i) a preprocessing stage to mark the electrodes tips and background subtraction; (ii) a segmentation stage to extract the electric field bridging formation in region of interest; (iii) a feature extraction stage to extract electric field bridging using feature descriptors, area, minor-axis and major-axis length (iv) a classification stage to identify the pre-breakdown and breakdown condition. System performance was evaluated using support vector machine (SVM), k-nearest neighbour (k-NN) and random forest (RF) and SVM provided the most promising accuracy that was 99%. The results show that the combination of three feature descriptors, area, minor-axis and major-axis length are the best features combination in identifying the transformer oil condition. In future work, further studies will be conducted to investigate the pattern of pre- and post-breakdown due to some similarity found in image pattern. Due to that, more feature descriptors will be identified to find a unique pattern between pre- and post-breakdown condition

Natural ester is a good substitute for mineral oil. It has been successfully applied in power transformers, and its application scale will continue to increase. With the aging of oil-paper insulation in transformers, moisture and impurity particles will inevitably be generated. In this paper, dry and wet mineral oil and natural ester samples, as well as dry and wet cellulose particles, were prepared. The accumulation behavior of the cellulose particles and the conductivity current in mineral oil and natural ester under a non-uniform dc electrical field were compared by using eight combinations of dry or wet cellulose particles and dry or wet insulation oils. The results show that the speed of the cellulose particles and the growth of impurity bridges are faster in wet mineral oil and natural ester, especially when the cellulose particles are also wet. The increase of electrical field strength accelerates the appearance of this phenomenon. The cellulose particle bridging phenomenon in the mineral oil is more significant than that in the natural ester. Under the same dc voltage, the saturated conductivity current in every mineral oil sample decreases as the electrode distance increases; however, the opposite phenomenon is observed in the natural ester samples. Moreover, the oil moisture content increase has a more significant influence on the saturated current and the dc breakdown voltage than the particles' moisture content increase. For the same particle concentration level, the natural ester has a lower conductivity current and a larger dc breakdown voltage than the mineral oil. The natural ester presents better resistance to particle pollution and better insulation properties than the mineral oil.

GaN vertical PiN diodes with different anode thicknesses were fabricated on three native GaN wafers with the same p-layer doping concentrations, and planar hybrid edge termination. The breakdown behavior in terms of the breakdown voltage and the electroluminescence were studied as functions of the anode thickness. A repeatable avalanche breakdown and highest breakdown voltage were measured with the thinnest anode of 300 nm and with the thinnest edge termination region. This indicates the efficacy of the nitrogen-implanted hybrid edge termination design that comprises of junction termination and guard rings hybrid design. As the anode thickness increases, the edge termination thickness increases, and the devices exhibit lower breakdown voltages and less robust breakdown characteristics, often destructive. From this study, we also conclude that a very high p-layer doping of 2 × 1019 cm−3 is not s practical doping level, because it is too sensitive to the edge termination thickness.

The purpose of this present study is to prepare a stable mineral-oil (MO)-based nanofluid (NF) for usage as a coolant in a transformer. Nanoparticles (NPs) such as hexagonal boron nitride (h-BN) and titanium oxide (TiO2) have superior thermal and electrical characteristics. Their dispersion into MO is likely to elevate the electrothermal properties of NFs. Therefore, different batches of NFs are prepared by uniformly dispersing the insulating h-BN and semiconducting TiO2 NP of different concentrations in MO. Bulk h-BN NP of size 1μm is exfoliated into 2D nanosheets of size 150–200 nm, subsequently enhancing the surface area of exfoliated h-BN (Eh-BN). However, from the zeta-potential analysis, NP concentration of 0.01 and 0.1 wt.% are chosen for further study. The thermal conductivity and ACBDV studies of the prepared NF are performed to investigate the cooling and insulation characteristics. The charging-dynamics study verifies the enhancement in ACBDV of the Eh-BN NF. Weibull statistical analysis is carried out to obtain the maximum probability of ACBDV failure, and it is observed that 0.01 wt.% based NF has superior cooling and insulation properties than MO and remaining batches of NFs.

The standard Large Deviation Theory (LDT) mirrors the Boltzmann-Gibbs (BG) factor which describes the thermal equilibrium of short-range Hamiltonian systems, the velocity distribution of which is Maxwellian. It is generically applicable to systems satisfying the Central Limit Theorem (CLT), among others. When we focus instead on stationary states of typical complex systems (e.g., classical long-range Hamiltonian systems), both the CLT and LDT need to be generalized. We focus here on a scale-invariant stochastic process involving strongly-correlated exchangeable random variables which, through the Laplace-de Finetti theorem, is known to yield a long-tailed Q-Gaussian N -> infinity attractor in the space of distributions (1 < Q < 3). We present strong numerical indications that the corresponding LDT probability distribution is given by P(N, z) = P-0 e(q)(-rq(z)N) = P-0[1 - (1 - q)r(q)(z)N](1/(1-q)) with q = 2 - 1/Q is an element of(1, 5/3). The rate function r(q)(z) seemingly equals the relative nonadditive q(r)-entropy per particle, with q(r) similar or equal to 7/10 + 6/10 1/Q-1, thus exhibiting a singularity at Q = 1 and recovering the BG value q(r) = 1 in the Q -> 3 limit. Let us emphasize that the extensivity of r(q)(z)N appears to be verified, consistently with what is expected, from the Legendre structure of thermodynamics, for a total entropy. The present analysis of a relatively simple model somewhat mirroring spin-1/2 long-range-interacting ferromagnets (e.g., with strongly anisotropic XY coupling) might be helpful for a deeper understanding of nonequilibrium systems with global correlations and other complex systems. (C) 2021 Published by Elsevier B.V., CNPq, Brazil; Faperj; TUBITAK (Turkish Agency) [121F269], The numerical calculations reported in this paper were par-tially performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources) . We acknowledge in-teresting remarks from E.M.F. Curado and R. Hanel, as well as partial financial support from CNPq, Brazil and Faperj (Brazil-ian agencies) . U.T. is a member of the Science Academy, Bilim Akademisi, Turkey and acknowledges partial support from TUBITAK (Turkish Agency) under the Research Project number 121F269.

PT APCB is an electronics company that produces electronic device components called Narrow Shaft. The purpose of this study is to evaluate the maintenance activity in a pre-turning machine by measuring the Overall Equipment Effectiveness (OEE) level. The OEE level is obtained based on the Availability, Performance, and Quality Rate of the pre-turning machine maintenance activities. In addition, the purpose of this study is to identify the causes of the ineffectiveness of pre-turning machine maintenance activities and provide improvement suggestions for maintenance effectiveness at PT APCB. Based on the results of the calculation of the OEE value it is known that the PT APCB company still has not reached the world standard of 85%. This shows that the company still has to improve maintenance activities in the pre-turning process. The calculation of OEE value shows that the lowest OEE level in February 2016 was 48.31%, while the highest OEE level in September 2016 was 83.23%. The low performance of the pre-turning machine process was due to the ineffectiveness of maintenance activities which were caused by 14 factors. The primary causal factor with the highest value is the bar feeder problem with the highest request frequency value of 250.

A new method to treat the inherent instability of Lanczos-type algorithms is introduced. It enables us to capture the properties of the sequence of iterates generated by a Lanczos-type algorithm by interpolating on this sequence of points. The interpolation model found is then used to generate a point that is outside the range. It is expected that this new point will link up the rest of the sequence of points generated by the Lanczos-type algorithm if breakdown does not occur. However, because we assume that the interpolation model captures the properties of the Lanczos sequence, the new point belongs to that sequence since it is generated by the model. This paper introduces the so-called Embedded Interpolation and Extrapolation Model in Lanczos-type Algorithms (EIEMLA). The model was implemented in algorithms A 13 /B 6 and A 13 /B 13 , which are new variants of the Lanczos algorithm. Individually, these algorithms perform badly on high dimensional systems of linear equations (SLEs). However, with the embedded interpolation and extrapolation models, EIEM A 13 /B 6 and EIEM A 13 /B 13 , a substantial improvement in the performance on SLEs with up to 10 5 variables can be achieved.

Toward the practical and rational insulation design of a resistive superconducting fault current limiter, it is necessary to consider the electrical breakdown (BD) due to the transient bubble generation in liquid nitrogen (LN 2 ) at the quench of the HTS materials. We have been investigating the intrinsic BD characteristics of LN 2 without bubbles and the dynamic BD characteristics of LN 2 under transient bubble disturbance, respectively. In this paper, we have investigated the dynamic BD characteristics of LN 2 for different electrode diameters and gap lengths, and have discussed in terms of the volume effect of dynamic BD strength.

In this paper, we report on achieving the first high performance lateral $\beta $ -Ga2O3 Schottky barrier diode (SBD) on sapphire substrate via transferring $\beta $ -Ga2O3 nano-membrane channel from a low dislocation density bulk $\beta $ -Ga2O3 substrate. Non field-plated lateral SBDs with Schottky–Ohmic contact distance of 4, 6, 11, and $15 \mu$ m demonstrate a reverse breakdown voltage (BV) of 0.64, 0.85, 1.2, and 1.7 kV with on resistance ( $R_\text {on}$ ) of 47, 66, 91, and 190 $\omega \cdot $ mm, respectively. This lateral $R_{\text {on}, \text{sp}}$ ~ BV performance is comparable to that of vertical SBDs. Combining with 107 ~ 108 high temperature current on/off ratio, $\beta $ -Ga2O3 SBD shows its great promise for power rectifying once the $\beta $ -Ga2O3 drift layer epitaxial growth becomes more mature.

The substantial improvements in transmission voltage, which have been adopted to meet fast-growing energy demands, require more reliable power equipment and higher-quality insulating materials. The polytetrafluoroethylene (PTFE) nozzle, as the key part of a high-voltage circuit breaker, is often subjected to arc ablation and breakdown phenomena. Thus, it is very urgent to develop nozzles with better performance. In this study, PTFE/boron nitride (BN) composites were prepared. The relationships among the BN filler loading, thermal transition properties, spectral reflectance properties, arc ablation resistance, and AC dielectric breakdown performances, as well as their corresponding mechanisms, were studied. Experimental results show that the thermal conductivity and thermal diffusivity of PTFE/BN composites increased monotonously with BN loading, and that both parameters were improved by 41% and 44%, respectively, for 11 wt % composites compared with pure PTFE. Moreover, PTFE/BN composites had higher light reflectance in the wavelength range from 320 to 2500 nm. The PTFE/BN composites presented better arc ablation resistance performance with increased BN loading, which was improved by 88.5%. It is thought that the increased thermal conductivity, thermal diffusivity, the strong light reflectance, and surface sediment after arc ablation contribute to the improvement in arc ablation resistance performance. The AC breakdown strength of PTFE/BN composites was enhanced by 30.93%, attributed to the good heat dissipation properties introduced by the BN fillers. Thus, filling BN into the PTFE matrix would be helpful to solve the equipment issue that comes from the improvement in transmission voltage.

Vacuum interrupter has a composite insulation system. When an internal insulation fails, the discharge has complex and various patterns. Previously, based on the discharge development characteristics, we proposed a discrimination method for the discharge pattern in vacuum interrupter. We measured the applied voltage, anode current, and shield potential waveforms, respectively. From the analysis of the measured waveforms, we can estimate the discharge patterns and discharge path lengths. In this paper, a non-contact shield potential measurement was proposed when the shield potential cannot be measured directly. Furthermore, verification tests with this measurement method were conducted and the effectiveness of the discrimination method was confirmed.

In this letter, we demonstrate a general model to reduce the reverse leakage current ( ${I}_{\text {R}}$ ) in high-voltage AlGaN/GaN Schottky diodes (SBDs) by engineering the pinchoff voltage ( ${V}_{\text {p}}$ ) of their field plates (FPs). The maximum voltage drop at the Schottky junction ( ${V}_{\text {SCH}}$ ) in the OFF state can be significantly decreased by reducing $\vert {V}_{p}\vert $ , which leads to a drastically diminished ${I}_{\text {R}}$ . We used a tri-gate architecture as means to control ${V}_{\text {p}}$ and, thus, ${I}_{\text {R}}$ , as it offers great flexibility to engineer ${V}_{\text {p}}$ compared with conventional schemes. $\vert {V}_{\text {p}}\vert $ of SBDs with tri-gate FPs was reduced by decreasing the width of the nanowires, which led to a very small ${I}_{\text {R}}$ , below 10 nA/mm under reverse biases up to 500 V, and an increase of over 800 V in soft breakdown voltage ( ${V}_{\text {BR}}$ ) at $1~\mu \text{A}$ /mm. These results reveal the importance of ${V}_{\text {p}}$ in reducing ${I}_{\text {R}}$ for SBDs, and unveil the potential of tri-gate structures as FPs for power devices.

In this letter, we introduce and demonstrate the concept of slanted tri-gates to enhance the breakdown voltage ( ${V}_{{\text {BR}}}$ ) in lateral GaN power devices. Conventionally, field plates (FPs) are used to enhance the ${V}_{{\text {BR}}}$ by distributing more homogeneously the electric field near the gate electrode, which is mainly determined by their pinch-off voltage ( ${V}_{\text {p}}$ ). These FPs however rely on a vertical approach, in which ${V}_{\text {p}}$ is usually designed via the thickness of the FP oxide. On the other hand, the slanted tri-gate relies on a lateral design to tailor its ${V}_{\text {p}}$ , by simply changing the width ( ${w}$ ) of their nanowires lithographically. Here, we demonstrate this concept for AlGaN/GaN-on-silicon MOSHEMTs resulting in an increase of ~500 V in ${V}_{{\text {BR}}}$ compared with the counterpart planar devices. These devices presented a high ${V}_{{\text {BR}}}$ of 1350 V with a small gate-to-drain separation ( ${L}_{{\text {GD}}}$ ) of $10~\mu \text{m}$ , along with a record high-power figure-of-merit of 1.2 GW/cm $^{{2}}$ among GaN-on-silicon lateral transistors.

Work orders for 40 tractors, collected by Hail Agricultural Development Company (HADCO), Saudi Arabia, were used in this study. Data for more than 1670 work orders were classified as repairs or maintenance. The relationship between tractor age and power on repair and maintenance costs was also investigated. A cost ratio (CR) term was developed by dividing the repair or maintenance cost by the tractor purchase price. This CR was used in all variables affected the repairs and maintenance costs. 51% of the work orders were classified as repair works while 49% were classified as maintenance jobs. The highest CRs were listed for both repair and maintenance. The 64 WJOs for transmission repairs had the highest CR, while electrical system repairs WJOs were 197 and had the lowest CR. That is because the costs of some parts were much affecting the CR and not the number of work orders. Similar results were obtained when calculating the classified maintenance CR. The repair CR was higher than that of the maintenance. Both repair CR and maintenance CR were directly related to tractor working life (age) and tractor power.

Cavitation breakdown at various liquid temperatures is one of the major problems encountered in the operations of centrifugal pumps. There are a number of practical cases where the pumps operate at high temperature or near the saturation temperature of the liquid. A detailed understanding of the factors affecting the breakdown of cavitation is essential for accurate performance prediction and design. The purpose of this paper is to present results of a cavitation breakdown investigation which are both experimental and theoretical. The present model based on Rayleigh-Plesset expression for bubble dynamics. The predicted model includes many important parameters controlling the cavitation breakdown such as bubble dynamics, flow rate, rotational speed, temperature and thermodynamics properties of water and the gas pressure inside the cavity. The present model has been tested against extensive present and earlier published experimental results in centrifugal pumps at various operating water temperatures and operating conditions. The comparison between the predicted breakdown blade cavitation number with the present and previous published experimental results showed a surprisingly good agreement. This agreement means that the roles played by many important parameters are consistent with the present model. Therefore, the present model represents an addition to knowledge in this aspect which could help the centrifugal pump user and designer to predict the breakdown cavitation performance at various operating conditions.

The majority of terrestrial net primary production decomposes, fueling detrital food webs and converting dead plant carbon to atmospheric CO2. There is considerable interest in determining the sensitivity of this process to climate warming. A common approach has been to use spatial gradients in temperature (i.e., latitude or elevation) to estimate temperature sensitivity. However, these studies typically relate decomposition rates to average temperatures at each site along such gradients, ignoring within‐site temperature variation. To evaluate the potential effects of temperature variation on estimates of temperature sensitivity, we simulated plant litter decomposition using both randomly generated and real time series of temperature. This simulation approach illustrated how temperature variation leads to higher decomposition rates at a given mean temperature than is predicted from simulations in which temperature is held constant. Increases in decomposition rate were most evident at cooler sites, where temporal variation in temperature tends to be greater than at warmer sites. This unbalanced effect of temperature variation shifted the slope of the relationships between average temperature and decomposition rate, resulting in lower estimated temperature sensitivities than were used to simulate decomposition. For example, estimates of activation energy (Ea) were as much as 0.15 eV lower than the true Ea when decomposition was simulated with the true Ea set to the canonical respiration value of 0.65 eV. We found that the estimated Ea was lower than the true Ea for surface, soil, and air temperatures, but not for stream temperatures, for which there was only a weak relationship between temperature variation and mean temperature. Our results suggest that commonly used methods may underestimate the temperature dependence of litter decomposition, particularly in terrestrial environments. We encourage publication of temperature data that include variation estimates and suggest an alternative method for calculating temperature sensitivity that accounts for variation in temperature.

Después de todo lo que he aprendido durante la carrera, he descubierto que lo que más me ha gustado y lo que más me ha llamado la atención a la hora de decidir a qué me gustaría dedicarme una vez salga al mercado laboral es la fase de preproducción de una pieza audiovisual ya sea, largometraje, cortometraje, capítulo de serie, etc. Pero, sobre todo, me ha gustado la preproducción de los capítulos de series de televisión como descubrí cuando realizamos la webserie ‘Sexto sin ascensor’. Es la práctica con la que más he disfrutado en el grado y me hizo ver que esa es mi vocación. Por eso, mi objetivo en este trabajo es experimentar con la preproducción de un capítulo piloto de una de las series que me gustan ‘Paquita Salas’, y así recordar cómo se realiza todo y también aprender cosas nuevas a la hora de documentarme para realizar el trabajo. Por ello, he encontrado el guion del capítulo piloto de la serie (en una web libre de derechos) y yo misma he generado el resto de documentos necesarios en una preproducción basándome en el guion: guion técnico, desglose, plan de rodaje… Mi TFG me ha resultado muy útil porque me ha permitido recopilar prácticamente todo lo necesario en una preproducción en un solo dossier y que me será de gran ayuda a la hora de realizar mis propios trabajos en el futuro. Con todo el trabajo que he llegado a realizar, me he sentido bastante profesional para ser una principiante. Creo que lo más relevante de este trabajo es que he llegado a crear yo misma todos los documentos necesarios con el único apoyo del guion literario gracias a todos los conocimientos que he adquirido en el grado y más concretamente en la asignatura de Dirección de Producción. Mi conclusión es que he sido capaz de recopilar el trabajo de preproducción en un solo dossier, y aunque una preproducción requiere de mucho más trabajo, al menos sirve como una guía de apoyo para principiantes como yo. Creo que con algo más de práctica podría llegar a realizar mis propios trabajos y aunque ahora mismo tengo poca experiencia profesional, finalmente llegaría a ser mi profesión After everything I have learned during my career, I have discovered that what I liked the most and what caught my attention the most when deciding what I would like to dedicate myself to once I enter the labor market is the pre-production phase of an audiovisual piece either, feature film, short film, series chapter, etc. But, above all, I liked the pre-production of the television series episodes, as I discovered when we made the web series ‘Sixth without a lift’. It is the practice with which I have most enjoyed in the degree and it made me see that this is my vocation. For this reason, my objective in this work is to experiment with the pre-production of a pilot episode of one of the series that I like 'Paquita Salas', and thus remember how everything is done and also learn new things when documenting myself to make the job. For this reason, I found the script for the pilot chapter of the series (on a royalty-free website) and I myself have generated the rest of the necessary documents in a pre-production based on the script: technical script, breakdown, shooting plan ... My Final Degree Project has been very useful to me because it allowed me to collect practically everything necessary in a pre-production in a single dossier and that will be of great help to me when doing my own work in the future. With all the work I have done, I have felt quite professional for a beginner. I think the most relevant thing about this work is that I could create all the necessary documents myself with the sole support of the literary script thanks to all the knowledge that I acquired in the degree and more specifically in the Production Direction subject. My conclusion is that I have been able to compile the pre-production work into a single dossier, and while a pre-production requires a lot more work, it at least serves as a supporting guide for beginners like me. I think that with a little more practice I could get to do my own jobs and although right now I have little professional experience, it would finally become my profession

A common definition of disaster management is difficult because the term disaster may refer to different situations, and the approaches to manage these situations can vary in scope and aim. A disaster usually refers to an unpredictable event with relevant negative consequences for people, businesses, and the environment. According to the magnitude of damages generated, disasters are detected from catastrophes. With reference to the speed of occurrence, disasters are classified as emergencies or not. Moreover, different literature streams focus on either industrial disasters, which are produced by companies in their ordinary activity (e.g., blow out of some plants) or natural disasters, which are incidence of natural hazard events (earthquakes, eruptions, floods, or cyclones). Managing a disaster is also a very broad definition, as the art of management can span from forecasting to preventing, planning, solving disasters, and recovering the situation as it was before the disaster or improving it (disaster recovery).

We report a systematic study of finite-temperature spin transport in quantum and classical one-dimensional magnets with isotropic spin interactions, including both integrable and non-integrable models. Employing a phenomenological framework based on a generalized Burgers' equation in a time-dependent stochastic environment, we identify four different universality classes of spin fluctuations. These comprise, aside from normal spin diffusion, three types of superdiffusive transport: the KPZ universality class and two distinct types of anomalous diffusion with multiplicative logarithmic corrections. Our predictions are supported by extensive numerical simulations on various examples of quantum and classical chains. Contrary to common belief, we demonstrate that even non-integrable spin chains can display a diverging spin diffusion constant at finite temperatures., Comment: Typos corrected, references added and new supplementary material A on the classical simulations